Flowing clear error messages from transforms
This one comes up every now and again, and although targeted at a specific group – those who use custom xsl for their transforms – as our very own Oleg Gershikov has a nice approach to it, it is worth repeating here -
You have an orchestration, in which you have a transform shape, and at runtime, the transform fails.
This usually results with a typical BizTalk error message – very detailed, and thus very useful – for those who can read it…
What you want is a clear, business related error message, how do you go about achieving that?
Well – to start with, you add some validation in your xsl script, and provide the relevant message, something along the lines of -
<xsl:message terminate="yes">Here’s some nice error message, hopefully this will mean something to somebody….</xsl:message>
Then, you make sure you have a scope around your transform shape, in which you catch the Microsoft.XLANGs.BaseTypes.TransformationFailureException exception
From that exception, you can extract the message provided by the script using -
if(xslex.InnerException != null)
event.Message = event.Message + "Exception details: " + xslex.InnerException.Message;
event.Message = event.Message + "Exception details: " + xslex.ToString();
and use that to change an error that previously looked something like -
Error encountered while executing the transform SomeTransform. Error:Transformation failed..Microsoft.XLANGs.Core.XTransformationFailureException: Error encountered while executing the transform SomeTransform. Error:Transformation failed.. ---> System.Xml.Xsl.XsltException: Transform terminated: '
Here’s some nice error message, hopefully this will mean something to somebody…. '.
at System.Xml.Xsl.XsltOld.MessageAction.Execute(Processor processor, ActionFrame frame)
at System.Xml.Xsl.XsltOld.ActionFrame.Execute(Processor processor)
at System.Xml.Xsl.XsltOld.Processor.Execute(Stream stream)
at System.Xml.Xsl.XslTransform.Transform(XPathNavigator input, XsltArgumentList args, Stream output, XmlResolver resolver)
at System.Xml.Xsl.XslTransform.Transform(IXPathNavigable input, XsltArgumentList args, Stream output, XmlResolver resolver)
at Microsoft.XLANGs.Core.Service.ApplyTransform(Type mapRef, Object outParams, Object inParams)
To something like this -
The process failed. Transformation Exception occurred creating request.Exception details: Transform terminated:
Here’s some nice error message, hopefully this will mean something to somebody….